21200388 has 48 divisors (see below), whose sum is σ = 56318976. Its totient is φ = 6144160.

The previous prime is 21200383. The next prime is 21200401. The reversal of 21200388 is 88300212.

It is not an unprimeable number, because it can be changed into a prime (21200381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 456 + ... + 6527.

It is an arithmetic number, because the mean of its divisors is an integer number (1173312).

Almost surely, 2^21200388 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21200388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28159488).

21200388 is an abundant number, since it is smaller than the sum of its proper divisors (35118588).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21200388 is a wasteful number, since it uses less digits than its factorization.

21200388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7024 (or 7022 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 21200388 is about 4604.3879072033. The cubic root of 21200388 is about 276.7671891622.

The spelling of 21200388 in words is "twenty-one million, two hundred thousand, three hundred eighty-eight".